Structure for coupling toothbrush head to electric toothbrush handle

ABSTRACT

This document discloses a coupling member for mounting a toothbrush head to an electric toothbrush. The coupling member includes a base having a first end with an opening for receiving a drive shaft of an electric toothbrush. The coupling member also includes a coupling section that extends from a second end of the base. The coupling section comprises a cylindrical sidewall that surrounds a cavity for receiving the drive shaft, and a set of teeth that extend into the cavity from the cylindrical sidewall along a longitudinal axis of the coupling section. This document also discloses a brush head incorporating such a coupling member, and an electric toothbrush to which such a brush head is attached.

RELATED APPLICATIONS AND CLAIM OF PRIORITY

This patent document claims priority to U.S. Provisional PatentApplications No. 63/053,960, filed Jul. 20, 2020. The disclosure of thepriority application is fully incorporated into this document byreference.

BACKGROUND

This disclosure relates to the field of electric toothbrushes, andparticularly brush heads that are configured to couple to an electrictoothbrush handle.

Many types of electric toothbrushes use high speed vibrations of themotor inside the toothbrush handle to drive the brush head. In order tooperate the electric toothbrush, the construction of the brush headrequires that it be tightly coupled to the drive shaft of the toothbrushhandle so it can withstand the high speed vibrations from operating thetoothbrush. Many existing products, therefore, use metal or springsinside the brush head to facilitate a tight coupling to the drive shaftof the toothbrush handle. This can increase the cost of making the brushhead.

In addition, while some brush heads avoid the use of metal springs,those brush heads can sometimes have difficulty staying connected to thehandle, and/or may not offer as much vibratory effect due to a loosefit.

This patent document describes an apparatus that addresses at least someof the issues described above and/or other issues.

SUMMARY

In a first aspect, this document discloses a coupling member formounting a toothbrush head to an electric toothbrush. The couplingmember includes a base having a first end with an opening for receivinga drive shaft of an electric toothbrush. The coupling member alsoincludes a coupling section that extends from a second end of the base.The coupling section comprises a cylindrical sidewall that surrounds acavity for receiving the drive shaft, and a set of teeth that extendinto the cavity from the cylindrical sidewall along a longitudinal axisof the coupling section.

Optionally, the base may include one or more mounting holes that areeach positioned to align with a corresponding mounting ridge of a stemof the toothbrush head. The coupling section may include a longitudinalridge that is positioned on the sidewall along the longitudinal axis ofthe coupling section and sized to engage with a channel inside of a stemof a toothbrush head. The cylindrical sidewall may be a closed sidewall,with no opening leading to the cavity, or it may include slits thatprovide an opening leading to the cavity, in which case a resilientspring member may be positioned between the two slits, and the teeth maybe positioned on the resilient spring member. The resilient springmember may extend all the way to the base, or an opening may existbetween the resilient spring member and the base so that the opening andslits together form a U-shape.

In a second embodiment, a coupling member for mounting a toothbrush headto an electric toothbrush includes a base having a first end with anopening for receiving a drive shaft of an electric toothbrush, alongwith a coupling section that extends from a second end of the base. Thecoupling section includes a cylindrical sidewall that surrounds a cavityfor receiving the drive shaft, an aperture in the cylindrical sidewallthat provides an opening to the cavity, and a resilient spring memberthat is sized to be positioned within the aperture and touch the driveshaft while being held by the aperture.

Optionally, in the second embodiment the resilient spring member mayinclude a base that and two sidewalls that are positioned so that, inoperation, the resilient spring member will touch the drive shaft andthe two sidewalls will touch and be held by the aperture. The distancebetween the two sidewalls of the resilient spring member when theresilient spring member is in a relaxed position may be greater than acorresponding dimension of the aperture. The base of the coupling membermay include one or more mounting holes that are each positioned to alignwith a corresponding mounting ridge of a stem of the toothbrush head.The coupling section of the coupling member may include a longitudinalridge that is positioned on the sidewall along the longitudinal axis ofthe coupling section and sized to engage with a channel inside of a stemof a toothbrush head. A set of teeth may extend into the cavity from thecylindrical sidewall along the longitudinal axis.

Any of the embodiments described above may be used with a toothbrushhead for an electric toothbrush, in which the toothbrush head includes abrush section that has a bristle tray and bristles that extend from thebristle tray. A stem extends from the brush section and defines a cavitytherein one or more mounting ridges on inside wall of the opening. Thecoupling member may be positioned inside the cavity of the stem. Any ofthe embodiments described above may be used with an electric toothbrushhaving a handle and a drive shaft, in which case the stem will extend tothe handle and the drive shaft will be inserted into the couplingmember.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a toothbrush head with a coupling memberconnected inside of it.

FIG. 2 is a perspective view of a coupling member.

FIG. 3 is an alternate perspective view of the coupling member of FIG.2.

FIG. 4 is a side view of the coupling member of FIG. 2.

FIG. 5 is a cross-sectional view of the coupling member of FIG. 2.

FIGS. 6A and 6B illustrate an alternate embodiment of a coupling member.FIG. 6C illustrates a variation of the embodiment shown in FIG. 6B.

FIGS. 7A and 7B illustrate how a spring may be used with the embodimentof FIGS. 6A and 6B.

FIG. 8 illustrates another alternate embodiment of a coupling member.

FIG. 9 is a bottom perspective view of the stem of a toothbrush headwith a coupling member according to the embodiment in FIG. 1 inside ofit

FIG. 10A is a cross-sectional view, and FIG. 10B is an exploded view,illustrating how the toothbrush head and its coupling member may attachto a toothbrush handle.

DETAILED DESCRIPTION

As used in this document, the singular forms “a,” “an,” and “the”include plural references unless the context clearly dictates otherwise.Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of ordinary skillin the art. As used in this document, the term “comprising” (or“comprises”) means “including (or includes), but not limited to.” Whenused in this document, the term “exemplary” is intended to mean “by wayof example” and is not intended to indicate that a particular exemplaryitem is preferred or required.

In this document, when terms such “first” and “second” are used tomodify a noun, such use is simply intended to distinguish one item fromanother, and is not intended to require a sequential order unlessspecifically stated. The term “approximately,” when used in connectionwith a numeric value, is intended to include values that are close to,but not exactly, the number. For example, in some embodiments, the term“approximately” may include values that are within +/−10 percent of thevalue.

In this document, the term “connected”, when referring to two physicalstructures, means that the two physical structures touch each other.Devices that are connected may be secured to each other, or they maysimply touch each other and not be secured.

When used in this document, terms such as “top” and “bottom,” “upper”and “lower”, or “front” and “rear,” are not intended to have absoluteorientations but are instead intended to describe relative positions ofvarious components with respect to each other. For example, a firstcomponent may be an “upper” component and a second component may be a“lower” component when a device of which the components are a part isoriented in a first direction. The relative orientations of thecomponents may be reversed, or the components may be on the same plane,if the orientation of the structure that contains the components ischanged. The claims are intended to include all orientations of a devicecontaining such components.

This disclosure is not limited to the particular systems, methodologiesor protocols described, as these may vary. The terminology used in thisdescription is for the purpose of describing the particular versions orembodiments only, and is not intended to limit the scope.

In various embodiments, a brush head 10 is couplable to a drive shaft ofan electric toothbrush handle, as shown in FIG. 10A. As shown in FIG. 1,The brush head 10 includes a bristle tray 12 that is a substrate fromwhich multiple attached bristles 16 extend. The brush head 10 also has astem 14, which extends from the bristle tray 12, leading to a base 17that flares outward from the stem. In use, the base will be placed overa drive shaft of an electric toothbrush handle.

The stem 14 and base 17 each have an opening that leads to a channel 15for receiving and mounting a coupling member 18. The coupling member 18is the structure that will receive and attach to the drive shaft of theelectric toothbrush handle.

One configuration for attachment of the coupling member 18 to the stem14 is further described in detail with reference to FIGS. 2-4, whichillustrate various views of a coupling member 18. The coupling member 18has a base 26 and a coupling section 22. The base 26 has an opening 27for receiving the drive shaft of an electric toothbrush handle. Theopening 27 is at one end (which may be referred to as a bottom end) ofthe base 26. The opposite end (which may be referred to as a top) of thebase 26 is the end from which the coupling section 22 extends. The topend of the base 26 has a diameter that is narrower than the diameter ofthe opening 27 so that the body flares outward as the distance from ahandle coupling section 22 increases. The base 26 has one or moremounting holes 28 a, 28 b that are positioned to engage with one or moremounting ridges (54 in FIG. 9) of the stem so that the coupling member18 can be mounted to the stem. Optionally, the mounting holes 28 a, 28 bmay be positioned directly opposite (i.e., approximately 180° away from)each other on the body as shown in FIGS. 3 and 4.

The coupling section 22 has a generally cylindrical sidewall 24 thatsurrounds a cavity 34 that will receive the drive shaft of the electrictoothbrush. Optionally, the sidewall 24 may be closed so that no openingexists from the outside of the coupling section 22 to the interiorcoupling section 22. Alternatively, the coupling section 22 may includean opening (as shown with coupling section 222 of FIG. 8 which will bedescribed in more detail below). In the embodiment shown in FIGS. 2-4,the coupling section 22 may include a longitudinal ridge 46 on anoutside surface of the sidewall 24 with an opening inside of it forreceiving the tip of the drive shaft. The longitudinal ridge 46 ispositioned and sized to engage with a longitudinal channel inside thestem (shown as 64 in FIG. 10A). A relatively narrow segment 46 a of thelongitudinal ridge will engage the longitudinal channel, and an optionalrelatively wide segment 46 b (i.e., relatively wider than the narrowsegment 46 a) may serve as a stop and limit the distance of travel ofthe longitudinal ridge 46 into the longitudinal channel 64. Thisengagement between the longitudinal ridge 46 and the longitudinalchannel 64 inside the stem prevents the coupling member from rotationalmovement about the axis of the stem. It further provides a guide tofacilitate the insertion of the coupling member into the stem.

Optionally, as shown in FIG. 3, the longitudinal ridge 46 may alsoextend longitudinally from the base 26 along outside surface of thesidewall 24 of the handle coupling section 22 of the coupling member tofurther enhance the engagement between the coupling member 18 and thestem and prevent rotational movement or twisting of the coupling memberrelative to the stem.

In the illustrated embodiment, the size and shape of the cross-sectionof the coupling section 22 may correspond to the size and shape of thestem 14 of the brush head 10, for example, at about ⅛ inch in diametermeasured from outside, with a length about ½ inch. The base 26 mayextend from the coupling section and flare outward to the opening 27 toform a semi-conical shape. The opening 27 may be of various sizes, forexample, at ½ inch in diameter as measured from outside at its widestpoint.

In various embodiments, multiple engagements between various parts mayadditionally facilitate the tight coupling between the brush head andthe coupling member. For example, in FIGS. 2-4, the coupling member 18may have one or more mounting blocks 33 extending from outside the base26 and that are positioned to engage with one or more mountingreceptacles 56 inside the channel 15 of the stem 14 (see FIG. 9). Thisengagement between each mounting block 33 and its corresponding mountingreceptacles 56 (in FIG. 9) will further lock the coupling member intoposition to prevent the coupling member from being pushed in or rotatingabout the axis of the stem.

Alternatively, and/or additionally, as shown in FIGS. 2-4, the couplingsection 22 may end with a tip 30 that has a diameter that is smallerthan that of the sidewall 24. The tip 30 meets the sidewall 24 at aledge 31. The tip 30 and ledge 31 further facilitate the coupling of thecoupling section 22 and the stem 14, and the ledge 30 serves as a stopto limit the distance of travel of the coupling member 22 into the stem14.

Alternatively, and/or additionally, the coupling member 18 may have anengagement means for further coupling the brush head to the drive shaftof the toothbrush handle. As shown in the coupling member'scross-sectional view of FIG. 5, this engagement means may include a gear40 that extends inward into a cavity 34 from the sidewall 24 and ispositioned to touch the drive shaft when the drive shaft is insertedinto the cavity 34 of the coupling section 22. The gear 40 is referredto as a gear because, as shown in FIG. 5, the gear 40 includes multipleteeth (i.e., bumps or other raised areas) that extend inward from thesidewall 24 along the longitudinal axis of the cavity 34. The teeth ofthe gear 40, when touching the drive shaft, provide friction that helpsto retain drive shaft of the electric toothbrush handle in place duringoperation. The teeth may be positioned in any location on the interiorsidewall. FIGS. 4 and 5 show that the gear 40 may be positioned along aninterior portion of sidewall 24 in a location that corresponds to thatof an indentation 39 to further increase engagement of the gear 40 withthe drive shaft. The teeth may be soft and/or resilient, to provide aspring function that allows the drive shaft to vibrate when the teethare positioned against the drive shaft. For example, the teeth may beformed of a soft plastic such as a low density polyethylene (LDPE),rubber, or other soft yet strong material. The entire coupling membermay be made of such material, or the teeth and other components of thecoupling member may be made of different materials.

FIGS. 6A-6B and 7A-7B illustrate an alternate embodiment of a couplingmember 118 that is similar in structure to that of FIGS. 2-4, with abase 126 and a coupling section 122 having a cylindrical sidewall 124.However, unlike the sidewall 24 of FIGS. 2-4, in FIGS. 6A-6B and 7A-7Bsidewall 124 includes one or more apertures 114 a that provide anopening that leads to the central cavity that receives the drive shaftof the electric toothbrush. As shown in FIG. 7A, a resilient spring 191may be inserted into the aperture 114 a and touch the drive shaft tohelp provide stability and transfer vibration to the stem of thetoothbrush head. Alternatively, resilient spring 191 may be insertedinto the other aperture 114 b and touch the drive shaft to help providestability and transfer vibration to the stem of the toothbrush head. Thespring 191 as shown may be U-shaped, with a flat or curved base fromwhich two sides extend. FIG. 7B is a cross-sectional view showing thespring 191 as it may be inserted into the cavity 134 within the sidewall124. The aperture locations and sizes shown in FIG. 6B are by way ofexample, and this embodiment is not limited to the specific apertureshape and size shown. For example, as shown in FIG. 6C, instead of asingle aperture 114 b along the side may include two or more apertures114 c, 114 e separated by a spacer 115 that forms part of the sidewallThe spacer may serve to hold the drive shaft in place and may optionallyhave teeth as described above, while the apertures 114 a, 114 c, 114 eprovide some room for movement of the drive shaft.

The spring 191 may be formed of a thin strip of metal or another strongyet resilient material. The spring 191 may be sized to extend into thecavity so that the flat or curved base, and the two sides that extendfrom the base, will be positioned around the drive shaft so that some orall of the spring's sides touch the drive shaft. The two sides thatextend from the base of the spring 191 will be flush with or extend onlyslightly beyond the aperture 114 a (or 114 b) of the sidewall 124 intowhich it is inserted. The base of the spring 191 will have dimensionsthat are equal to or slightly smaller than that of the aperture. Thesides of the spring 191 may flare slightly outward so that the maximumdistance between the sides is slightly larger than a corresponding sizeof the aperture 114 when the spring 191 is in a relaxed position. Thespring 191 may thus be squeezed to be inserted into the aperture andrelaxed to be held in place by a friction fit at the aperture 114 a (or114 b).

FIG. 8 illustrates an alternate embodiment of a coupling member 218 suchas that shown in U.S. Pat. No. 9,827,079, the disclosure of which isincorporated into this document by reference. As shown in FIG. 8, thecoupling member 218 has a base 226, which has an opening 227 forreceiving a drive shaft of the electric toothbrush handle. The base 226may have one or more mounting holes 228 that are positioned to engagewith one or more mounting ridges of the stem so that the coupling membercan be mounted to the stem. The coupling member 218 also may have one ormore mounting blocks 230 extending from outside the base 226 and thatare positioned to engage with one or more mounting receptacles insidethe opening of the stem.

The coupling member 218 also has a coupling section 222, which has asidewall 224 with a cavity 234 inside of it. The sidewall 224 has atleast two longitudinal slits 236 that form a resilient wall 238 inbetween. The resilient wall 238 is positioned to touch the drive shaftof the electric toothbrush handle when the drive shaft is inserted intothe cavity 234 inside the sidewall 234 and exert a return force inwardtowards the drive shaft to achieve a tight coupling with the driveshaft. The resilient wall 238 may extend all the way down to and touchthe base 226 as shown, or an opening may exist between the resilientwall 238 and the base 226 so that the two longitudinal slits 236 and anopening between the resilient wall 238 and the base 226 form a U-shape.

Alternatively, and/or additionally, the coupling member 218 of FIG. 8may have an engagement means for further coupling the brush head to thedrive shaft of the toothbrush handle. This engagement means may includea raised portion 240 that extends inward from the resilient wall 238 andis positioned to touch the drive shaft when the drive shaft is insertedinto the cavity 234 of the coupling section 222. The raised portion 240,when touching the drive shaft, will also raise the resilient wall 238outward, thus to increase the inward returning force of the resilientwall 238, whereby a tighter coupling between the coupling member and thedrive shaft of the electric toothbrush handle can be achieved.

Further, the interior wall of the resilient wall 238 may include teeththat serve as a gear, as with gear 40 of FIG. 5.

As shown in FIG. 9, the channel 15 of the stem 14 may open at a baseplatform 50. FIG. 1 illustrates that the opening 27 of the base 26 ofthe coupling member 18 may also have a base platform 29 that ispositioned to be flush with, or slightly offset within the stem from,the base platform 50 of the stem 14 when the coupling member and thestem are fully engaged.

FIG. 10A is a cross sectional assembled view, and FIG. 10B is anexploded view, each that together illustrate that the stem 14 of thebrush head 10 includes a channel 15 for receiving the coupling section22, which in turn has a cavity 34 for receiving the drive shaft 91 ofthe toothbrush handle 90. The coupling section 22 is inserted into thechannel 15 at the base 17 of the brush head 10. Although theillustration in FIGS. 10A-10B shows the coupling section 22 of FIGS.2-4, any of the coupling member embodiments described in this documentmay be used in the configuration shown in FIGS. 10A-10B.

The various embodiments disclosed in this patent document provideadvantages over the prior art, whether standalone or combined. Forexample, the resilient wall of the handle coupling section of thecoupling member that is positioned to engage with the drive shaft of theelectric toothbrush handle may be made from the same wall of the handlecoupling section of the coupling member, which requires no metal springor other separate resilient member. This both achieves a tight coupling(because there is no separate part) and reduces the cost of making.Further, multiple engagements of various parts of the stem and thecoupling member all facilitate a tight coupling between the couplingmember and the stem, and thus improve the stability of the brush head asit is operating under the high speed vibrations of the motor inside thehandle.

Further, the toothbrush head may be easy to manufacture as all the partscan be made of plastic or polyester materials. The cone shaped openingof the stem may facilitate easy receiving and coupling of the couplingmember into the stem, and multiple engagement means, such as, thelongitudinal ridge of the coupling member and the correspondinglongitudinal channel in the stem, the mounting channel of the couplingmember and the corresponding ridge block in the stem, the raisedresilient wall of the coupling member and the corresponding couplingchannel in the stem, the mounting block of the coupling member and thecorresponding mounting channel in the stem, the base ring of thecoupling member and the mating sitting platform in the stem, themounting holes of the coupling member and the mounting ridges in thestem, each may facilitate easy sliding and positioning of the couplingmember into the stem and secure mounting of the coupling member to thestem.

Other advantages of the present invention can be apparent to thoseskilled in the art from the foregoing specification. Accordingly, itwill be recognized by those skilled in the art that changes ormodifications may be made to the above-described embodiments withoutdeparting from the broad inventive concepts of the invention. It shouldtherefore be understood that this invention is not limited to theparticular embodiments described in this document, but is intended toinclude all changes and modifications that are within the scope andspirit of the invention as defined in the claims.

The invention claimed is:
 1. A coupling member for mounting a toothbrushhead to an electric toothbrush, the coupling member comprising: a basehaving a first end with an opening for receiving a drive shaft of anelectric toothbrush; and a coupling section that extends from a secondend of the base, wherein the coupling section comprises: a cylindricalsidewall that surrounds a cavity for receiving the drive shaft, and aplurality of teeth that extend into the cavity from the cylindricalsidewall along a longitudinal axis of the coupling section, wherein thecylindrical sidewall is a closed sidewall, with no opening leading tothe cavity.
 2. The coupling member of claim 1, wherein the basecomprises one or more mounting holes that are each positioned to alignwith a corresponding mounting ridge of a stem of the toothbrush head. 3.The coupling member of claim 1, wherein the coupling section comprises alongitudinal ridge that is positioned on the cylindrical sidewall alongthe longitudinal axis of the coupling section and sized to engage with achannel inside of a stem of a toothbrush head.
 4. The coupling member ofclaim 1, wherein: the cylindrical sidewall further comprises anindentation on the exterior of the coupling member.
 5. The couplingmember of claim 4, wherein the teeth are positioned in a location alongan interior portion of the sidewall that corresponds to the location ofthe indentation.
 6. The coupling member of claim 4, wherein theindentation extends along the coupling section and touches the base. 7.A toothbrush head for an electric toothbrush, the toothbrush headcomprising: a brush section comprising: a bristle tray, and a pluralityof bristles that extend from the bristle tray; a stem extending from thebrush section, wherein the stem defines a channel therein and comprisesone or more mounting ridges on an inside wall of the channel; and acoupling member positioned inside the cavity of the stem, wherein thecoupling member comprises: a base having a first end with an opening forreceiving a drive shaft of an electric toothbrush, and a couplingsection that extends from a second end of the base, wherein the couplingsection comprises: a cylindrical sidewall that surrounds a cavity forreceiving the drive shaft; and a plurality of teeth that extend into thecavity from the cylindrical sidewall along a longitudinal axis of thecoupling section, wherein the cylindrical sidewall is a closed sidewall,with no opening leading to the cavity.
 8. The toothbrush head of claim7, wherein the base of the coupling member comprises one or moremounting holes that are each positioned to align with a correspondingone of the mounting ridges.
 9. The toothbrush head of claim 7, whereinthe coupling section comprises a longitudinal ridge that is positionedon the cylindrical sidewall along the longitudinal axis of the couplingsection and sized to engage with the channel inside of the stem.
 10. Thetoothbrush head of claim 7, wherein: the toothbrush head furthercomprises an indentation on the exterior of the coupling member.
 11. Thetoothbrush head of claim 10, wherein the teeth are positioned in alocation along an interior portion of the sidewall that corresponds tothe location of the indentation.
 12. The toothbrush head of claim 10,wherein the indentation extends along the coupling section and touchesthe base.
 13. An electric toothbrush comprising: a handle; a driveshaft; and a toothbrush head comprising: a brush section comprising: abristle tray; and a plurality of bristles that extend from the bristletray, a bristle tray, a plurality of bristles that extend from thebristle tray, a stem extending from the brush section to the handle,wherein the stem defines a channel therein and comprises one or moremounting ridges on an inside wall of the channel, and a coupling memberpositioned inside the cavity of the stem, wherein the coupling membercomprises: a base having a first end with an opening into which thedrive shaft is inserted; and a coupling section that extends from asecond end of the base, wherein the coupling section comprises: acylindrical sidewall that surrounds a cavity for receiving the driveshaft, and a plurality of teeth that extend into the cavity from thecylindrical sidewall along a longitudinal axis of the coupling section,wherein the cylindrical sidewall is a closed sidewall, with no openingleading to the cavity.
 14. The electric toothbrush of claim 13, wherein:the toothbrush head further comprises an indentation on the exterior ofthe coupling member.
 15. The electric toothbrush of claim 14, whereinthe teeth are positioned in a location along an interior portion of thesidewall that corresponds to the location of the indentation.
 16. Atoothbrush head comprising: a stem comprising a cavity configured toreceive a drive shaft of an electric toothbrush; an interior sidewallthat surrounds the cavity; a plurality of teeth integrally formed withthe interior sidewall, wherein the teeth abut at least part of the driveshaft when the toothbrush head is in its assembled state with the driveshaft; and an indentation positioned exterior to the teeth, so as tofurther increase engagement of the teeth with the driveshaft.